US3576236A - Tandem hydraulic brake actuator - Google Patents

Tandem hydraulic brake actuator Download PDF

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Publication number
US3576236A
US3576236A US803153*A US3576236DA US3576236A US 3576236 A US3576236 A US 3576236A US 3576236D A US3576236D A US 3576236DA US 3576236 A US3576236 A US 3576236A
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US
United States
Prior art keywords
piston
control
bore
floating piston
face
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Expired - Lifetime
Application number
US803153*A
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English (en)
Inventor
Bernard Laverdant
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DBA SA
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DBA SA
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Publication date
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/38—Slack adjusters
    • F16D65/40—Slack adjusters mechanical
    • F16D65/52—Slack adjusters mechanical self-acting in one direction for adjusting excessive play
    • F16D65/56—Slack adjusters mechanical self-acting in one direction for adjusting excessive play with screw-thread and nut
    • F16D65/567—Slack adjusters mechanical self-acting in one direction for adjusting excessive play with screw-thread and nut for mounting on a disc brake
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
    • F16D65/16—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake
    • F16D65/18—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position arranged in or on the brake adapted for drawing members together, e.g. for disc brakes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2121/00—Type of actuator operation force
    • F16D2121/02—Fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2121/00—Type of actuator operation force
    • F16D2121/14—Mechanical
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2123/00—Multiple operation forces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2125/00—Components of actuators
    • F16D2125/18—Mechanical mechanisms
    • F16D2125/20—Mechanical mechanisms converting rotation to linear movement or vice versa
    • F16D2125/22—Mechanical mechanisms converting rotation to linear movement or vice versa acting transversely to the axis of rotation
    • F16D2125/26—Cranks

Definitions

  • a tandem hydraulic brake actuator having in a bore a brake actuating piston responsive to a first hydraulic control pressure, a floating piston responsive to the pressure differential between said first and second control pressures so as to move said control piston in a brake-applying direction in the event of a failure in said first control pressure, a slack adjuster operatively provided between said pistons and means operative to prevent actuation of said floating piston as long as the pressure differential acting thereon is below a predetermined value.
  • the main object of the invention is to provide a compact tandem hydraulic brake actuator arrangement avoiding the above drawbacks and permitting generating substantially equal brakeapplying forces when actuated by anyone of two separate control pressures respectively.
  • a tandem hydraulic brake actuator for a split braking control system adapted to supply at least two separate hydraulic control pressures characterized by comprising in a cylinder bore a movable control piston responsive to one of said two separate control pressures and adaptedto be moved thereby in a brakesapplying direction, a floating piston responsive to the pressure differential between said two control pressures so as to be moved in a brake-applying direction by the other of said control pressures when said differential pressure is above gagement with said partition wall as long-as the differential pressure acting on said piston .is below said predetermined value.
  • FlG. l is a cross-sectional view of a floating type stirrup for a disc brake including a tandem brake actuator according to the invention.
  • FIG. 2 isa cross-sectional view with parts broken away of a second embodiment of a tandem brake actuator more particularly adapted for a disc brake stirrup provided with a handticularly adapted for a disc brake of the reaction frame type.
  • FIG. 1 there is shown a unitary caliper or stirrup 10 comprising a brake actuator generally designated by reference numeral l2 and comprising a piston 14 the outer face of which is provided to be appliedagainst a pad (not shown), the other pad (also not shown) bearing against a reaction arm 16 of caliper 10.
  • a brake actuator generally designated by reference numeral l2
  • piston 14 the outer face of which is provided to be appliedagainst a pad (not shown), the other pad (also not shown) bearing against a reaction arm 16 of caliper 10.
  • Anybody conversant in the art knows very well brakes of this type in which a floating or sliding caliper straddles the pads and the disc located between said pads.
  • Piston 14 is mounted in a bore 18 provided in the body of v caliper 10, the sealing between the bore and the piston being obtained by means of a ring .20 also providing the return of piston 14.
  • a piston 24 which will be designated as floating piston, piston 14 being called control piston.
  • pistons 14 and 24 defined in bore 18 two chambers 26 and 28.
  • Chamber 26 is defined by bottom 22 of stirrup l0 and floating piston 24 and chamber 28 is defined by the face of the floating piston 24 opposite to one which is adjacent to the bottom and the rear face of piston 14.
  • Fluid inlets 30 and 32 connected to distinct pressure fluid systems open into chambers 26 and 28 respectively.
  • Bottom 22 comprises a cylindrical portion projecting out of said bottom, said portion 34 cooperating with a blind hole provided in piston 24. and comprising in its inner wall a groove in which is located a sealing ring 35.
  • Projecting portion 34 is preferably located concentric with respect to piston 24.
  • means opposing the rotation of piston 24 about its axis said means consisting in the shown example of a pin 36 projecting out of the bottom and entering piston 24.
  • a connection constituting a unidirectional adjusting device which is such-that as the pads of the brake wear, the piston 14 moves away from piston 24, the unidirectional device opposing the two pistons from coming closer to each other.
  • a device consists, in the shown example of a threaded rod 38 solid with piston 24 or integral with the latter on which is threadedly mounted a sleeve 40.
  • the thread between sleeve 40 a and rod 38 is of the reversible type and the pitch is very long.
  • Sleeve 40 is capable of a slight displacement with respect to piston 14; to this effect there is provided a washer 42 maintained by a snap ring located in a groove provided in the inner wall of the piston.
  • a thrust ball bearing 44 is located between washer 44 and a flange portion 46 of sleeve 40, said thrust bearing having for its object to facilitate the rotation of the sleeve.
  • a helical spring 48 is wound around sleeve 40 with a slight clamping action and one of the ends of said spring is anchored in the recess 50 provided in the piston. The rotation of the piston is opposed thanks to the cooperation of a projection provided on the pad (not shown) with a rectilinear groove 52 provided on the external face of piston 14.
  • Spring 48 constitutes a unidirectional clutch permitting the rotation in the lenghtening direction of the assembly threaded rod -sleeve and opposing the rotation in the opposite direction.
  • the inlet ports 30 and 32 are fed from two distinct master cylinders or from a split-type master cylinder with fluids under two pressures that are substantially equal.
  • the floating piston 24 is applied against the bottom 22 and that there exists friction forces opposing displacement of said piston, only the pressure acting in chamber tends to move piston 14 toward the disc which results in the application by reaction of the two pads against the opposite faces of said disc.
  • the automatic adjusting device operates and the distance increases between piston 14 and piston 24. The latter remaining normally applied against bottom 22.
  • piston 24 is only more firmly pressed against bottom 22.
  • FIG. 1 there has been shown a piston 24 maintained by friction and differential pressure against bottom 22 but, of course, the projections 34 could be avoided by providing the end portion of bore 18 with an area slightly less than the one of the rest of the bore in such a manner that the pressures appliedto inlets 30 and 32 being substantially equal a stepped piston 24 be only subjected on its face defining chamber 26 to a relatively small force whereas its face defining chamber 28 would be submitted to a larger force.
  • floating piston 24 comprises on its face opposite the one which carries threaded rod 38 a cylindrical projection 60 extending through the bottom 22 with provision of a seal 62. Piston 24 is urged toward bottom 22 by resilient washers 64 clamped between bottom 22 and a snap ring 66 secured to the cylindrical projection 60.
  • the end of projection 60 comprises a slot in which is located a pivoting link 68 cooperating with a rotating cam means 70, the rotation of which in the direction of arrow A provides the motion of the assembly of piston 24 and 14 in the braking direction, cam means 70 being connected to a handbrake control.
  • piston 24 is urged toward the bottom 22 by pressure differential when the pressures applied to inlet ports 30 and 32 are substantially equal and further more because of the friction forces existing between cylinder 60 and bottom 22 and also because of the resilient washers 64 provided to urge the whole structure toward bottom 22. With respect to the rotation of piston 24 about its axis, this rotation is opposed thanks to the shape of link 68 engaging the slot of cam means 70.
  • FIG. 3 relates to a caliper for a brake which does not comprise any hand control.
  • the same reference numerals are used to designate elements which are substantially the same as those already described in FIG. I.
  • the piston 24 the rotation of which is opposed by pin 36 comprises on its face adjacent to bottom 22 a resilient ring 72 mounted in a groove which is preferably coaxial with bore 18, said ring cooperating with the wall of bottom 22.
  • the brake actuator that is shown with the same reference numerals designating elements similar or identical to those of FIGS. 1 to 3 is provided to actuate a disc brake of the reaction frame type.
  • the bottom of bore 18, designated by reference numeral 22a is no longer solid with cylinder itself which in the embodiment of FIGS. 1 to 3 was integral with the stirrup 10.
  • Bottom 22a is slidably mounted in a bore 18 and its external face opposite to the one in contact with the fluid in chamber 26 engages a frame made of a sheet of metal having a substantial thickness.
  • Reaction frame disc brakes are well known by the one skilled in the art.
  • the operation of the device of FIG. 4 is the following:
  • piston 24 In case of failure of the system connected to inlet port 30, piston 24 is no longer pressure balanced and thus transmits the efforts due to the pressure in chamber 28 to the frame 80 through the intennediary of projection 60, link 68 and cam means 70.
  • FIG. 1 there is not shown any embodiment relating to a fixed stirrup disc brake comprising opposed cylinders but the man skilled in the art will understand that there can be easily provided two devices of the type shown in FIG. 1 symmetrically located with respect to the plane of disc to pennit applying the invention in the case of a fixed stirrup disc brake with opposed cylinders.
  • a wheel cylinder for drum brake comprising two pistons similar to piston 14 mounted with their external faces projecting out of a through bore 18 of a wheel cylinder, the two pistons 14 being separated from each other by a floating piston of the same type as piston 24 but comprising symmetrically on both faces threaded rods 38 cooperating with unidirectional type adjusting devices.
  • a piston similar to piston 14 a first unidirectional adjusting device connecting to piston 14 with floating piston similar to piston22 and then another unidirectional adjusting device connecting the floating piston 24 to another piston similar to control piston 14, the latter engaging by its external face the free end of the other shoe of the drum brake.
  • the unidirectional devices are such that the control pistons similar to piston 14 are adapted to move away from floating piston 24 without being capable of moving toward each other as the linings of the shoes or the drum brake wear.
  • a housing defining a bore therewithin
  • control piston slidable in said bore and responsive to fluid pressure in said first hydraulic system to be urged in a brake-applying direction thereby;
  • a unidirectionally extendible force transmitting element H disposed within said bore between said pistons for allow- 1 ing said floating piston to urge said control piston in a brake-applying direction upon a failure in said first hydraulic system;
  • annular seal operatively arranged between said other face of said floating piston and the wall of said bore to prevent fluid pressure in said second hydraulic system from acting upon the area of said other face defined within said seal, whereby said other face of said floating piston presents a smaller effective area against which fluid pressure may act than does said one face.
  • a hydraulic brake actuator according to claim 1, wherein an olfcenter pin is provided between said cylinder bore and said floating piston for opposing relative angular displacements between the floating pistons and said control piston.
  • a hydraulic brake actuator according to claim 1, and preloaded resilient means operatively arranged between a relatively fixed portion of the housing and said floating piston for normally biasing the latter in engagement with a relatively fixed abutting surface.
  • a hydraulic brake actuator according to claim 3,
  • said relatively fixed abutting surface is comprised of a cam surface on a movable control member pivotally mounted on said housing and adapted to be connected to auxiliary brake control means.
  • a hydraulic brake actuator according to claim 1, wherein said annular sealing means is arranged between a tubular projection extending axially from said other face and the central cylindrical opening of an annular partition wall sealingly arranged in said cylinder bore.
  • a hydraulic brake actuator according to claim 5, wherein the free end of said tubular piston projection is adapted to engage a cam surface on a movable control member pivotally mounted on said housing to be connected to an auxiliary brake control means.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Braking Arrangements (AREA)
US803153*A 1968-03-06 1969-02-28 Tandem hydraulic brake actuator Expired - Lifetime US3576236A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR142612 1968-03-06

Publications (1)

Publication Number Publication Date
US3576236A true US3576236A (en) 1971-04-27

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ID=8647087

Family Applications (1)

Application Number Title Priority Date Filing Date
US803153*A Expired - Lifetime US3576236A (en) 1968-03-06 1969-02-28 Tandem hydraulic brake actuator

Country Status (7)

Country Link
US (1) US3576236A (de)
JP (1) JPS4947219B1 (de)
DE (1) DE1911287C3 (de)
ES (1) ES364446A1 (de)
FR (1) FR1569727A (de)
GB (1) GB1219380A (de)
SE (1) SE335261B (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3724616A (en) * 1971-04-22 1973-04-03 Bendix Corp Tandem cylinder disc brake
US3773148A (en) * 1971-03-19 1973-11-20 B A Paris Sa D Hydraulic brake actuator for a disc brake
US3818804A (en) * 1971-12-13 1974-06-25 Weatherhead Co Dual brake system
US4565265A (en) * 1985-01-25 1986-01-21 General Motors Corporation Hydraulic parking brake
US20090208272A1 (en) * 2006-02-21 2009-08-20 Klaus Hofmann Clamping and/or braking device

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2092751B1 (de) * 1970-06-16 1974-03-22 Dba
US3995722A (en) * 1975-02-18 1976-12-07 Abex Corporation Fail-safe disc brake having a slack adjuster mechanism
JPS5813765B2 (ja) * 1975-10-17 1983-03-15 トキコ株式会社 ブレ−キシリンダソウチ
CN106907410B (zh) * 2017-04-25 2019-01-15 玉环凯凌集团有限公司 一种制动钳

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2497438A (en) * 1946-10-01 1950-02-14 Dunlop Rubber Co Fluid operated disk brake
FR1469777A (fr) * 1966-02-22 1967-02-17 Teves Kg Alfred Frein à disque hydraulique avec dispositif de freinage manuel
US3465852A (en) * 1967-02-15 1969-09-09 Teves Gmbh Alfred Floating-yoke disk brake for dual-network vehicle brake system
US3476220A (en) * 1967-07-13 1969-11-04 Aisin Seiki Hydraulic disc brake apparatus and multiple operators therefor
US3490565A (en) * 1966-11-16 1970-01-20 Teves Gmbh Alfred Piston assembly for dual-network disk-brake system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2497438A (en) * 1946-10-01 1950-02-14 Dunlop Rubber Co Fluid operated disk brake
FR1469777A (fr) * 1966-02-22 1967-02-17 Teves Kg Alfred Frein à disque hydraulique avec dispositif de freinage manuel
US3490565A (en) * 1966-11-16 1970-01-20 Teves Gmbh Alfred Piston assembly for dual-network disk-brake system
US3465852A (en) * 1967-02-15 1969-09-09 Teves Gmbh Alfred Floating-yoke disk brake for dual-network vehicle brake system
US3476220A (en) * 1967-07-13 1969-11-04 Aisin Seiki Hydraulic disc brake apparatus and multiple operators therefor

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3773148A (en) * 1971-03-19 1973-11-20 B A Paris Sa D Hydraulic brake actuator for a disc brake
US3724616A (en) * 1971-04-22 1973-04-03 Bendix Corp Tandem cylinder disc brake
US3818804A (en) * 1971-12-13 1974-06-25 Weatherhead Co Dual brake system
US4565265A (en) * 1985-01-25 1986-01-21 General Motors Corporation Hydraulic parking brake
US20090208272A1 (en) * 2006-02-21 2009-08-20 Klaus Hofmann Clamping and/or braking device
US8061488B2 (en) * 2006-02-21 2011-11-22 Klaus Hofmann Clamping or braking device

Also Published As

Publication number Publication date
JPS4947219B1 (de) 1974-12-14
DE1911287A1 (de) 1969-10-02
SE335261B (de) 1971-05-17
ES364446A1 (es) 1971-02-01
DE1911287C3 (de) 1979-08-16
DE1911287B2 (de) 1977-10-13
GB1219380A (en) 1971-01-13
FR1569727A (de) 1969-06-06

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